Grinding apparatus specially applicable for grinding the interior of the a-tubes of guns



J. W. BARNES.

mmnms APPARATUS SPECFALLY APPLICABLE FOR emunme THE nmmoa OF THE A TUBES 0F Gums.

APPLICATION FILED OCT,1I918.

Patented Apr. 6, 1926.

UNITED STATES PATENT OFFICE.

JOHN WILLIAM BARNES, OF ROCK FER-RY, BIRKENHEAD, ENGLAND.

GRINDING AIPPARATUS SPECIALLY APPLICABLE FOR GRINDING THE INTERIOR OF THE A-TUBES OF GUNS.

Application filed Bctobcr 1, 1818.

To all whom it may concern Be it known that I, J OHN VILLIAM BARNES, a subject of the King of Great Britain, and a resident of Rock Ferry, Birkenhead, England, have invented certain new and useful Improvements in and Relating to Grinding Apparatus Specially Applicable for Grinding the Interior of the A-Tub 3 of Guns, of which the following is a specification.

In the present usual methods of gun manufacture the interior of the A tube 01"- a gun is required to be formed with a slight taper and with a series of shoulders to receive the inner tube, the exterior of which is shaped to conform to the inner surface of the A tube. Owing to the slight taper required on the interior of the A tube the operation of boring this interior and of turning the exterior of the inner tube to correspond, is one which requires the utmost skill, and such highly skilled labor being limited the output of such pieces is correspondingly restricted. Even with such high skilled labor the interior of the A tube may not be bored truly conical. The object of the present invention is to provide an apparatus by means of which the bore of the A tube may be ground to a true conicality, thus eliminating the present necessity of the skilled labor required for the accurate boring or" the A tube. Further, owing to the slight inequalities which obtain in the bore of the A tube even in the case of highly skilled work. the exterior of the inner tube has to be turned with corresponding inequalities to produce an accurate fit. By insuring that the bore 01"? the A tube is ground perfectly true, the operation of finishing the exterior of the inner tube may be simplified, this inner tube also being then ground on its exterior and readily finished to be a true fit in the bore of the A tube.

According to this invention a grinding apparatus is provided consisting preferbly, of an outer tubular casing which may be screwed together in sections. Within the outer casing is fitted an inner tube surrounding the driving spindle which carries the grinding wheel, which inner tube may also be put together in sections, and besides sup i orting the bearings of the driving spindle is utilized as an oil bath. The driving spindle is constructed in sections, the junctions of which are supported within the Specification of Letters Patent.

Patented Apr. 6, 1920.

Serial No, 256,424.

bearings and detachably engage together in the manner of a dog clutch. The grinding whee-l end of the driving spindle is carried in a floating socket bearing and means may be provided for specially lubricating this bearing from the oil bath.

A rinding apparatus in accordance with this invention is shown in the accompanying drawings, in which Figure l is an outside view of the grinding apparatus complete. Fig. 2, Fig. 2 and Fig. 2" showing the apparatus to an enlarged scale, the upper parts of these views being in medial section and the lower parts in elevation, the three views showing respectively the driving pulley end, the middle portion, and the grinding wheel end of the apparatus, which have been subdivided ior convenience of illustration. Fig. -23, is a perspective view of the adjust able socket, Fig. i, a similar view of the floating bearing, Fig. 5, a view of the oiling ring for the bearing, and Figs. 6 and 7 perspective views showing the dog clutch engagement or the ends of the sections of the driving spindle.

in carryim out the invention the grinding apparatus is preferably inclosed in an outer tubular casing 1 which when of great length may be screwed together in sections connected by stepped bushes 2. Vithin the outer casing is an inner tube 3 which may also be put together in sections connected by screwed sleeves at. The driving spindle 5 passes through the inner tube 3, and is divided into sections, the ends of which 6 are formed in the manner of a dog clutch Figs. 6 and T and detachably engage to gether. These junctions of the driving spindle are supported within bearings 7 preferably of the ball r ce type, the outer elements 8 of the races being gripped between the sections 3 of the inner tube. In order also to permit of the driving spindle alining itself truly axiall the outer race of the bearing upon which the balls run may be made curved. The spindle 5 is fitted at one end with a driving pulley 9 or the like, said spindle being mounted in a ball race 10, and the outer end of said spindle is supplied with a grinding wheel 11 of any suitable construction. The end of the spindle carrying the grinding wheel is journaled in a bearing of the swivel type, such that it may float in its socket and permit the grinding wheel end of the spindle to a-line itself axially. This bearing is made in two parts 12, 13, forming an internal double conical socket, the parts having opposite intermeshing teeth 14: and a continuous external thread, by which the two parts of the socket may be screwed into the end of the inner tube 3. The end of the spindle 5 is carried in a bearing 15 having tapered shoulders 16 on an enlarged central portion which shoulders are held between the conical faces of the sockets 12, 13, in such manner that the bearing 15 may fioat in the socket and permit the spindle to aline itself correctly when rotating. The two parts of the socket 12, 13, are provided with intermeshing teeth 14 in order that compensation may be made to take up wear. The external thread being continuous and formed when the socket parts are in a normal position, if, say, the right-hand part of the socket be detached from the other part and the part 12 ad vanced angularly in the direction of the thread a distance of one tooth and the parts replaced together with the teeth engaging, when the two parts of the socket are then screwed into the inner tube 3 the parts will have been drawn together slightly closer thus compensating for wear of the engaging conical surfaces and shoulders. The outer tubular casing 1 is preferably arranged to support the center tube only at both ends and in the middle, such outer casing for this purpose being fitted with diaphragms 17, 18, at the driving wheel end and in the middle, which centralize the inner tube 3, a screwed wedge element 19 being fitted at the grinding wheel end which centralizes the end of the inner tube. The inner tube 3 besides supporting the bearings 7, is utilized as an oil bath, being flooded with oil for this purpose, and in order to provide for oiling the swivel bearing 15 at the front of the grinder, an annular helical spring 20, or analogous device, is fitted around the exterior of one end of the bearing, as shown, and a collar 21 formed on the spindle, by means of which oil is lifted from the bath, wiped off the collar by the stationary coiled ring 20, and conducted by way of inclined grooves 21 in the bearing piece 15 to the front end of the spindle which is thus lubricated. In order to prevent oil from this front bearing passing out to the grinding wheel a tubular apron 22 r may be carried from the wheel projecting into an annular socket.

A brass or soft metal pin 23 is fitted in the bearing piece 15 and engages in one of the spaces of the opposed teeth 14: in order to prevent the bearing piece 15 from rotating, but in the event of this bearing piece seizing on the shaft, the pin 23 will be sheared and permit the bearing piece to rotate.

In operation the outer casing is carried in a housing mounted on the saddle of a lathe or the like, the apparatus being supported about its center of gravity so that it is balanced with reference to the housing support, the long overhang of the casing being thus counterbalanced.

The grinding apparatus being supported in its housing and inserted in the gun tube, the cut is initially put on, and the subsequent tapering path of the grinding wheel is controlled from a master plate which is engaged by some suitable mechanism on the slide rest of the lathe, the profile of the master plate automatically guiding the wheel to grind the bore of the tube.

In such an apparatus the interior wall of the tube or similar part of a gun may be quite accurately ground to any taper or contour determined by the profile of the master plate, and consequently the extreme accuracy of turning or boring at present requisite in the manufacture of guns may to a considerable extent be dispensed with, and an increased output insured.

I claim.

Apparatus for grinding the interior of tubes, comprising, a driving spindle, a tube inclosing the spindle, bearings in the tube supporting the spindle, a grinding wheel on one end of the spindle, and a bearing for the grinding wheel end of the spindle consisting of a two part socket separately screwing into and adjustable in the inclosing tube, the said socket pieces having coned recesses to receive a shouldered bearing piece within which the spindle rotates, intermeshing members on the socket parts, relative angular displacement of the socket parts causing relative axial displacement of such parts when subsequently screwed into the tube, to compensate for wear.

In testimony whereof I affix my signature in presence of two witnesses.

JOHN WILLIAM BARNES.

Witnesses A. J. DAVIES, WILLIAM PIERCE. 

